Acute-Phase Proteins and Iron Status in Cats with Chronic Kidney Disease

J Vet Intern Med. 2017 Mar;31(2):457-464. doi: 10.1111/jvim.14661. Epub 2017 Jan 31.

Abstract

Background: The role of inflammation in the development and progression of chronic kidney disease (CKD) in cats is not well characterized. Hepcidin is a recently discovered acute-phase protein (APP) that plays an important role in iron metabolism and contributes to the development of anemia in humans with CKD.

Objectives: To compare serum APP concentrations, iron status, and erythropoietin (EPO) concentrations in healthy cats and cats with naturally occurring CKD.

Animals: A total of 18 healthy control cats and 38 cats with CKD.

Methods: Prospective study. After complete physical examination and routine blood analysis, the following tests were performed: serum amyloid A (SAA), haptoglobin (HAP), EPO, serum iron and ferritin concentration as well as total iron-binding capacity (TIBC). Serum hepcidin-25 concentration was measured by ELISA kit designed for use in humans.

Results: Mean SAA and hepcidin concentrations were significantly higher and mean total iron and TIBC were significantly lower in the CKD group (P < .05). There was a significant positive correlation between serum creatinine concentration (CRT) and 2 of the APPs (SAA and hepcidin; P < .05). Increases in SAA and hepcidin were associated with decreases in TIBC and hematocrit in the CKD group. Fourteen (37%) of the cats with CKD were anemic, and these cats had significantly lower TIBC (P < .05), suggesting a functional iron deficiency. There was no association between survival time and APP, iron status, or EPO concentrations.

Conclusions: Our data suggest that CKD in cats is associated with systemic inflammation and altered iron metabolism. With further validation in cats, hepcidin assays may help better characterize these relationships.

Keywords: anemia; erythropoietin; ferritin; hepcidin; serum amyloid A.

MeSH terms

  • Acute-Phase Proteins / analysis*
  • Anemia, Iron-Deficiency / veterinary*
  • Animals
  • Case-Control Studies
  • Cat Diseases / blood*
  • Cats
  • Erythropoietin / blood
  • Female
  • Ferritins / blood
  • Hematocrit / veterinary
  • Hepcidins / blood
  • Iron / blood*
  • Male
  • Prospective Studies
  • Renal Insufficiency, Chronic / blood
  • Renal Insufficiency, Chronic / veterinary*
  • Serum Amyloid A Protein / analysis

Substances

  • Acute-Phase Proteins
  • EPO protein, human
  • Hepcidins
  • Serum Amyloid A Protein
  • Erythropoietin
  • Ferritins
  • Iron